Fatigue analysis of catenary contact wires for high speed trains

Challenge E: Bringing the territories closer together at higher speeds
C
B
z
D
y
Wear
A
E
Figure 13. Virtual contact wire section.
The numerical result, illustrated in Figure 14, is different from measurements for waves which precede
and follow the pantograph passage.
It can be explained by differences of French and Japanese catenaries and pantographs or by different
damping ratio in catenary or by differences of frequency bandpass between measurements and
software [8].
Bending strain amplitude (x10 -6 )
600
400
200
0
-200
Time
Figure 14. Contact wire bending stress amplitude computed with OSCAR © .
Nevertheless, the maximum and minimum bending strain amplitudes due to peak are similar and thus
these results are good enough to make a preliminary fatigue analysis.
A criterion based on the Goodman's theory [9] is used, assuming an uniaxial loading. Although this
assumption is not verified, it is applied in order to identify the most critical zone in the catenary as a
preliminary study.
To apply this criterion, the maximum value and the minimum value of the longitudinal stress is
calculated for each node of the mesh, using respectively
max
x,
y,
z,
t min x,
y,
z,
t .
and
max
t
xx
Secondly, the criterion is applied and the point P(x,y,z), corresponding to the maximum value of
a
0.3 max
max
min
is identified, with
a
x, y,
z
.
2 3
2
The criterion can be expressed in a better known form as:
b
a
a m
where a is the tensile strength and b is the fatigue limit.
The result of this study, applied on French catenary and shown in Figure 15, illustrates that the
highest values of the criterion are closed to support represented by vertical dotted lines on Figure 15.
min
t
xx